问题 填空题

某小组为了验证复分解反应发生的条件,选用了下列部分药品进行实验.

①氢氧化钠溶液   ②硫酸铜溶液  ③稀盐酸  ④硝酸钾溶液

(1)为了验证有水生成的复分解反应能发生,某同学选择了①和③.你认为除上述四种药品外,还需增加的一种试剂是______.

(2)选择______(填序号)两种物质进行实验,能验证有沉淀生成的复分解反应能发生,其化学方程式______.

(3)下列反应中,能验证有气体生成的复分解反应能发生的是______(填序号).

A.锌与稀硫酸反应                    B.天然气燃烧

C.石灰石与稀盐酸反应                D.过氧化氢分解.

答案

(1)氢氧化钠溶液和稀盐酸反应生成氯化钠和水没有明显的现象,应该借助指示剂,还需增加的一种试剂是紫色石蕊试液;故填:紫色石蕊试液;

(2)氢氧化钠溶液和硫酸铜溶液反应生成氢氧化铜沉淀和硫酸钠,其化学方程式2NaOH+CuSO4=Cu(OH)2↓+Na2SO4;故填:①②;2NaOH+CuSO4=Cu(OH)2↓+Na2SO4

(3)复分解反应是指两种化合物相互交换成分生成另外两种化合物.而锌与稀硫酸反应生成氢气和硫酸锌,是单质和化合物反应生成另外的单质和化合物,属于置换反应;天然气燃烧生成二氧化碳和水是单质和化合物反应生成两种化合物,不属于复分解反应;过氧化氢分解生成氧气和水,是一种物质反应生成两种物质,属于分解反应;石灰石与稀盐酸反应生成氯化钙、水和二氧化碳,属于复分解反应,且有气体生成.故填:C.

阅读理解

Chinese people take their food and eat it extremely seriously .Eating is a communal (公共的),social, human experience in China .Sharing a meal is a sign of friendship,and trust , Eating plays a central role in friendship ,business ,medicine ,family and love. In short, food is life.

When eating, the rice is separated into your own personal bowl, but the dishes are placed in communal bowls in the center of the table and everybody help themselves with chopsticks .It's considered polite, and sign of respect and friendship, to encourage other people to eat plenty of the good bits, even to pick up food with your chopsticks and drop it into their rice bowls for them.

Food is an important component of weddings, funerals and almost all Chinese festivals. New Year is the time for dumplings, the Dragon Boat Festival is the time for sticky rice Zongzi wrapped in leaves, and Mid -Autumn Day is the time for Moon Cakes. The dinner table is the best for forum(公共讨论场所) to close business deals ,and it's the number one thing to do with friends.

Chinese women express their admiration for the opposite sex by cooking delicious meals of many courses, and these days it's the other way round too.

In short, if you want to get to know Chinese people, understand Chinese culture and thinking and get into Chinese life, you have to eat and appreciate Chinese food.

小题1: What is the best title of this passage?

A.Eating Food in China

B.How Do Chinese People Eat Food

C.The Importance of Chinese Food

D.Different Foods for Different Chinese Food小题2:In the first paragraph, what does the author mean by saying "food is life"?

A.Without food, there will be no life

B.food is as important as life

C.we must take food seriously

D.we must eat food every day小题3:What is the representative food for the Dragon Boat Festival in China?

A.Dumplings

B.Moon Cakes

C.Jiaozi

D.Zongzi

单项选择题